Conveyer flight



Sept. 11, 1930. J. D. CHRISTIAN CONVEYER FLIGHT Filed Feb. 4, 1924 PH gale/$ 7717 Patented Sept. 16, 1930 PATENT OFFICE JOSEPH D. CHRISTIAN, OF SAN FRANCISCO, CALIFORNIA CON VEYER FLIGHT Applicatidn filed February 4, 1924. Serial No. 890,417.

. The invention relates to a flight for a screw conveyer or spiral conveyer.

An object of the invention is to provide a conveyer flight which will possess greater 6 Wearing qualities than conveyer flights as heretofore made.

Another object of the invention is to provide a. cast steel conveyer flight.

A further object of the invention is to provide a manganese steel conveyer flight.

Another object of the invention is toprovide a cast steel conveyer flight provided with means for securing it to the contiguous edge of the adjacent flight.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description, where I shall outline in full that form of my invention which I have selected for illustration in the drawings accompanying and forming part of the present specification. In said drawings I have shown one form of flight embodying my invention and one modification thereof, but it is to be understood that I do not limit myself 1 to such form, since the invention, as set forth in the claims, may be embodied in a plurality of forms.

Referring to said drawings:

Figure 1 is a plan view of one form of cast steel annular disc, from which the helicoidal flight of my invention is produced.

Figure 2 is a side elevation of the disc shown in Figure 1.

Figure 3 is a side elevation of a modified form of disc adapted to form the end flight of the conveyer.

Figure 4 is a diametrical cross section of the annular disc shown in Figure 1.

Figure 5 is a cross section, on an enlarged scale of one side of the annulus.

Figure 6 is a cross section on an enlarged scale of one side of a modified form of annulus.

Figure 7 is a perspective view of the helicoidal flight formed from the cast disc.

Figure 8 is a side elevation of a screw conveyer formed of a plurality of contiguous helicoidal flights. 0 Figure 9 is a cross section through'the conveyer shaft with the conveyer arranged thereon, showing one form of joint connecting the conveyer flights together and to the shaft.

The object of the present invention is to produce a screw conveyer which will have a much longer life than screw conveyers as heretofore manufactured. This object I accomplish in two ways, both of which contribute'to the increased life of the conveyerw so I have provided a method whereby the helicoidal flight of the conveyer may be made of manganese steel, an accomplishment which manufacturers of manganese steel contended could not be done. I have also formed the flight of an increasing thickness from its inner edge to its outer edge, thereby increasing the thickness of metal at that part of the flight which is subjected to wear. The preferred form offlight of my invention embodies both ofthese features, but it is to be understood that the invention includes the features separately, since the use of either of the features separately greatly increases the life of the conveyer.

In accordance with my invention, I cast a split annular disc 12 of steel, preferably manganese steel. The cross section of the annulus is preferably such that the inner edge 13 of the annulus is of lesser thickness than the outer edge 14. The increase in thickness from the inner edge to the outer edge may be uniform as is shown in Figure 5, or it may be non-uniform as shown in Fig ure 6. The greatest amount of wear on the flight is produced at the outer two-thirds of the flight and in the construction shown in Figure 6 the outer two-thirds of the flight are of uniform thickness and the inner onethird of the flight is of gradually decreasing thickness to the inner edge 13. The decrease in thickness to the inner edge permits this edge to stretch when the plate is squeezed into helicoidal shape.

These successive flights may be secured together in any desirable manner to produce the complete conveyer and this may be accomplished by butt welding or by the use of rivets and butt straps or by other means. In the form of disc shown in Figures 1 and 2,

I have formed a lap or flange 16 at one end of the split disc, and this flange will overlie the contiguous end of the next adjacent flight when the flights are assembled to produce the complete conve era Rivet holes 17 may also be cast in the ange and in the other end of the split disc to receive rivets for securing the successive flights together. Lugs 18 of any suitable form or sha e may be cast integral with the disc for t e purpose of pro viding means for securing the flight to the shaft 19 upon which the flight is mounted. The flight which is to form the end flight of the conveyer may be provided on one end with a hollow boss 21 to receive a bolt which extends into the shaft for the purpose of securing the end of the flight of the shaft.

After the disc 12 has been formed, and has cooled, itis then squeezed into the form of the helicoidal flight shown in Figure 7. When the disc is made of manganese steel it is squeezed while cold into the form of the flight, but when the plate is made of other steel it may be heated and squeezed while hot. In the squeezing operation the length of the inner edge 13 and the length of the outer edge 14 are increased so that the flight extends for more than one complete revolution. Theflight 22'shown in Figure 7 is of increasing thickness from the inner edge 13 to the outer edge 14 and is formed with the flange or lap 16 for securing the flight to the next adjacent flight. Since the length of each flight is greater than one complete revolution, the jointsbetween the successive flights progress around the complete conveyer so that the load on the joint is dis- .tributed. By forming the flight in this manner, the flights fit the shaft-tightly and act as braces to stiffen and strengthen the shaft.

It is to be understood that the invention is not limited to the use of manganese steel since a flight of increasing thickness outwardly, when made of any steel, possesses advantages over'flights which are of the same helicoidal plate and a boss on each end of the plate, t e bosses being displaced radially to different extents, sothat the bosses will be radially alined with similar bosses on contiguous flights.

3. A screw conveyer flight comprising a. helicoidal plate, a projection on one end of the plate at its outer periphery, a boss on the rear side of the pro ection, a projection on the other end of the plate at its inner. periphery and a boss on the rear side of the latter proJection.

In testimony whereof, I have hereunto set my hand. I

JOSEPH D CHRISTIAN.

thickness throughout, or of decreasing thickness outwardly. It is further to be understood that the invention isnot limited-to a flight of increasing thickness outwardly since a flight of manganese steel of the same thickness throughout possesses advantages over flights of similar nature formed of other kinds of steeL- In Figure 9 I have shown a form of flight joint which possesses several advantageous features. The drawing shows the abutting ends of two flights, the edges being shown spaced apart to more clearly illustrate the structure. The ends of the flights are rabbeted so that they overlap in the lane of the conveyer at the joint. The over apping portion on one flight is provided with a cored boss 23 and the overlapping portion of the other flight is provided with a cored boss 24, the bosses being in alinement when the 

